Dead things were once living, such as a dead plant. Non-living things were never alive, like coal.
Answer:
The correct option is A) will make no difference in the survival of life if there were major changes in the environment.
Explanation:
Due to genetic diversity, variations in species are caused which makes some organisms of a species to be better adapted than other members of the species. These variations cause organisms to survive when differences in the environment occur. Although the allele frequencies might change due to the changes in the environment but the phenomenon of genetic diversity allows life to sustain on earth even when conditions will become unfavourable.
Answer:
(C) Aminoacyl-tRNA synthetases have an additional active site that binds to non-cognate tRNAs. The tRNAs that bind to this second active are hydrolyzed and released from the enzyme.
Explanation:
In case of translation, proof reading is done by aminoacyl-tRNA synthetases only. Aminoacyl-tRNA synthetases have two mechanisms to avoid error during translation which are mentioned as under:
<u>(1) Chemical proof reading:</u> Incorrect amino acids rather than being hydrolyzed in catalytic pocket get hydrolyzed in editing pocket and thus they hardly get attached to tRNA.
For example: For distinguishing similar amino acids like isoleucine and valine, isoleucyl-tRNA synthetase uses a second active site which is meant for only valine not for isoleucine. In this particular site, valine which had entered the enzyme is cleaved away with the help of editing reaction after which the enzyme is well prepared to process isoleucine which is the correct amino acid for this enzyme.
<u>(2) Kinetic proof reading: </u>Even if an incorrect amino acid has entered a particular aminoacyl-tRNA synthetase, it does not cause appropriate conformational change in the enzyme because of which the incorrect amino acid loosens from the enzyme and does not get incorporated.
Note: In this example, only chemical proof reading is mentioned not kinetic proof reading.
Answer:
False
Explanation:
Gram stain technique is a method use to classify bacteria into large groups base on their different cell wall components. It differentiate gram positive and gram negative by coloring them with red or Violet colors.
Gram stain is use for identification and classification of bacteria.
Gram positive stain violet due to presence of thick layers of peptidoglylcan in their cell walls and gram negative stain red due to thin layers of peptidoglylcan in their cell walls.
1) making haploid cell for sexual reproduction
2)it's long story u can read miosis in text books im sure u will undrestand it if u want I can suggest u some books
3)befor meiosis in interphase
in bacterial cells dividing cell into two control the number of chromosomes in cell in if binary fission takes long time the chromosome of bacteria will replicate again and cell will contain 3 chromosomes from main chromosome but in eukaryotic cell there is inhibition after dna replication that avoid cell to do that
4)2 times
5)I couldn't understand your question
